#commit_form {
    /* height: 20vh; 移除固定高度 */
    margin-left: auto; /* 使得div居中对齐而不是固定在920px的位置 */
    margin-top: 10rem;
    display: flex; /* 应用flex布局 */
    flex-direction: column; /* 子元素垂直排列 */
    justify-content: space-between; /* 子元素间隔均匀分布 */
    margin-bottom: 1rem;

}

.flash-success {
    color: #155724;
    background-color: #d4edda;
    border-color: #c3e6cb;
    padding: .75rem 1.25rem;
    margin-bottom: 1rem;
    border: 1px solid transparent;
    border-radius: .25rem;
}
